The study examined the clinical characteristics and conditions of care for patients with acute aortic syndrome (AAS) that will identify patients at risk for increased morbidity and mortality and provide a basis for the eventual achievement of specific studies on the optimal therapeutic management according to different risk profiles. The aim of the Observatory is to provide a photograph "size" of practices in France at present, both in the larger centers than in smaller and optimize diagnostic and therapeutic currently available by the activation pathways of rational management.